What is homologous series? Mention its characteristics.
Answers
Homologous series in organic chemistry is a group of organic compounds that differ from each other by one methylene group.
The characteristics are that the members of the group has same functional group.
The physical properties gradually increase or decrease due to increase in molecular mass.
The member of homologous series can be prepared by same or common general method of preparation. Two consecutive members of the group differs each other in the composition by CH2 unit.
Answer:
definition of homologous series : -
A series of compounds of the same family in which each member has the same type of carbon skeleton and functional group, and differs from the next member by a constantndifference of one methylene group (- CH_2 - )nin its molecular and structural formula is called as homologous series. An individual member of a homologous series is called homologue.
Characteristics of homologous series are :
(1) Each member of the homologous series can be represented by a general formula.
(2) Homologues have same functional groups and similar chemical properties.
(3) Two successive homologues differ by one-CH_2 (methylene) unit and hence molecular weight of each successive member differs by 14.
(4) All the members of a homologous series can be prepared by similar methods.
(5) Physical properties (like melting point, boiling point, density) of the homologues show a gradual change with increase in the molecular weight of the member. Example : Homologous series of alcohols have general formula C_n H_2n+_1OH.